When you upgrade from TFS 2005 to TFS 2008, if your project has strong name setup then building your solution from TFSBuild might throws error:
Target "ResolveKeySource" in file "C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets" from project "e:\build\abc\ccc.csproj":
Using "ResolveKeySource" task from assembly "Microsoft.Build.Tasks, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
Task "ResolveKeySource"
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: The "ResolveKeySource" task failed unexpectedly.
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: System.InvalidOperationException: Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: at Microsoft.Build.Shared.ExceptionHandling.RethrowUnlessFileIO(Exception e)
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: at Microsoft.Build.Tasks.ResolveKeySource.ResolveAssemblyKey()
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: at Microsoft.Build.Tasks.ResolveKeySource.Execute()
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Microsoft.Common.targets(1728,7): error MSB4018: at Microsoft.Build.BuildEngine.TaskEngine.ExecuteInstantiatedTask(EngineProxy engineProxy, ItemBucket bucket, TaskExecutionMode howToExecuteTask, ITask task, Boolean& taskResult)
Done executing task "ResolveKeySource" -- FAILED.
Following below step will resolve the issue:
1. Login to the build machine as Build Service account
2. Start commandline and run you project ccc.csproj using MSBuild
MSBuild.exe e:\build\abc\ccc.csproj /t:rebuild
3. It should prompt for signing key password, type you password that will export the key
4. They try to build it from TFSBuild.